Joe Henson

Research Interests

My research focuses on the search for a quantum theory of gravity (QG), and foundational questions in quantum mechanics that relate to that. I have most recently been interested in "causal dynamical triangulations", in which spacetimes are approximated using "gluings" of equilateral triangles (or tetrahedra, etc.), making it possible to define a QG theory and find some physically relevant observable quantities by computer simulations. I have benn involved with reformulating this theory in 2 dimensions, and in investigating whether the theory approximates to Einstein's theory of gravity in the appropriate regime, using simulations. I am also working on the causal set approach, in which spacetime is replaced at a more fundamental level by a discrete set of ``elements'' distinguished only by their causal relations with one another. I have been searching for observational consequences of this hypothesis. In foundations, I have been investigating definitions of causality and how they relate to quantum theory in the light of Bell's theorem.

Positions Held

October 2005 - September 2007 : Postdoctoral researcher, Spinoza Institute, University of Utrecht, the Netherlands.

October 2003 - September 2005: Postdoctoral researcher, Mathematics department
of the University of California, San Diego, USA.

The Causal set approach to quantum gravity, in 'Approaches to Quantum Gravity: Towards a New Understanding of Space and Time'. Edited by D. Oriti. Cambridge University Press, 2006. arXiv: gr-qc/0601121

Seminars

Causal sets: Discreteness without symmetry breaking, Foundations of Space and Time (reflections of quantum gravity), Cape Town, August 2009